Keep your passport in a safe place.  It is an important document.  Most passports are good for a limited period of time.  Your passport must be valid at all times while you are in the United States. It is your responsibility to know when it will expire and to contact the nearest Consulate or Embassy of your country.  Your passport can only be extended by your government and it usually takes several weeks for a passport to be renewed, so be sure to allow enough time.  Remember that you are in this country illegally when your passport expires.